Autosomal recessive, unknown cause, resembling (X-linked) dyskeratosis congenita. Marked variability in clinical presentation and course. Cells hypersensitive to dysfunctional clastogenic alkylating agents and to oxygen-induced free radicals. This test is used for prenatal diagnosis of FA. Studies: correlating clinical and cytogenic data from complementation analysis of euploid somatic cell hybrids; causes and potential correction of retarded growth and marrow failure; mapping the FA gene(s).